1. Technical Field
This disclosure relates generally to passive wireless data communication devices, and more particularly, to devices, system and methods for wirelessly providing electromagnetic energy for energizing passive wireless data communication devices.
2. Description of the Related Art
Conventional wireless data communication devices such as radio frequency identification (RFID) devices come in two general types, active and passive. Active wireless data communication devices have a consumable internal power storage device (e.g., battery), which is used to power the internal circuitry of the wireless data communication device for broadcasting a signal to an automatic data collection device. Passive wireless data communication devices, on the other hand, do not have a consumable internal power storage device. Such wireless data communication devices include an antenna that receives electromagnetic energy at a radio frequency. The antenna induces an electrical current that powers internal circuitry of the passive wireless data communication device and powers transmitting a signal to an automatic data collection device.
The global use of wireless data communication devices is increasing annually, as is, the number and types of applications in which they are used. Exemplary uses of wireless data communication devices include smart passports, smart identification cards, product tracking, animal identification, and inventory systems, to name a few.
In many situations, such as product tracking, it is desirable to read/interrogate a wireless data communication device by bringing an automatic data collection device to the wireless data communication device instead of the other way around. For example, when tracking products in a warehouse environment, it is generally easier to read/interrogate a pallet loaded with products in place with a portable automatic data collection device than it is to move the pallet of products to a stationary automatic data collection device. In addition to ease of use, it may be economically desirable to use portable automatic data collection devices instead of stationary automatic data collection devices because, for example, it may be faster for a person to move down an aisle reading from good-after-good than is to bring all of the individual goods to a stationary automatic data collection device.
Some conventional portable automatic data collection devices are shaped, sized, and configured to be hand-held by a user. Such automatic data collection devices may be used by couriers and personnel in a warehouse to name a few. These portable automatic data collection devices are typically battery powered. The battery provides the energy necessary for the hand-held automatic data collection device to read/interrogate passive wireless data communication devices and to energize passive wireless data communication devices.
A problem with conventional portable hand-held automatic data collection devices is that current batteries are generally insufficient to power a portable hand-held automatic data collection device for an extended period of time when the automatic data collection device is heavily used. It is generally not practical to increase the duty time, i.e., the amount of time over which a portable hand-held data collection device may be used, of a hand-held portable automatic data collection device by merely increasing the battery size. The size and weight of a portable hand-held automatic data collection device is generally limited by the desire that the portable hand-held automatic data collection device be small and light such that the portable hand-held automatic data collection device does not become too burdensome on the user of the portable hand-held automatic data collection device.
In some situations, such as at a checkout register, it may be practical to have a hand-held automatic data collection device that is connected by wires to a power source such as an electrical grid. However, the length of the wires limit the range of motion of the hand-held automatic data collection device thereby making such a hand-held automatic data collection device impractical for many situations such as in a large warehouse where the user may need to roam over large distances or for use by a delivery man.
Thus, there exists a need for a method and system that allows a hand-held automatic data collection device to be truly portable, wherein a truly portable hand-held automatic data collection device does not have a limited range of motion. There also exists a need to extend the duty time for a portable hand-held automatic data collection device. Furthermore, the need to address the aforementioned deficiencies of current portable hand-held automatic data collection devices, and other deficiencies, will only be exacerbated by the annual increase of the number of wireless data communication devices being used.